Fix jupyterlab-myst (tornado), or remove from build

[mattcen]

Description

jupyterlab-myst is included by 3217ae2, but when trying to install it, I get an error about failure to find a suitable build of tornado:

Reproduce

%pip install jupyterlab-myst

ValueError: Can't find a pure Python 3 wheel for 'tornado>=6.2.0'.
See: https://pyodide.org/en/stable/usage/faq.html#micropip-can-t-find-a-pure-python-wheel
You can use `micropip.install(..., keep_going=True)`to get a list of all packages with missing wheels.

Expected behavior

jupyterlab-myst installs successfully

Context

• JupyterLite version: Tested on https://jupyter.org/try-jupyter/lab/

[jtpio]

Thanks @mattcen for reporting.

jupyterlab-myst used to be working with JupyterLite fine at some point: #1021

This issue likely comes from the dependency on jupyter_server: https://github.com/executablebooks/jupyterlab-myst/blob/23d2aba01353f02843cb298dd0361ff1b45b01db/pyproject.toml#L25

Which was added in executablebooks/jupyterlab-myst#155

In the meantime we might want to pin on an earlier version, for example jupyterlab-myst<2.

[jtpio]

Pinning on jupyterlab-myst<2 should help for now, and is also recommended until there is a new release of JupyterLite using the JupyterLab 4 packages (#1019):

[agoose77]

Fixed by jupyterlab-myst>=2.0.2

[jtpio]

Nice!

Maybe we can bump the extension here:

jupyterlite/examples/jupyter_lite_config.json

Line 19 in fa5f44f

"https://conda.anaconda.org/conda-forge/noarch/jupyterlab-myst-0.1.6-pyhd8ed1ab_0.tar.bz2",

[agoose77]

Oh, I hadn't quite internalised that jupyterlite isn't yet on 4.0. That PR will have to wait for a bit, it seems :)